Allah, the Exalted, has said: "O you who believe! When you stand for prayer, then (while performing ablution) wash your faces and your hands up to the elbows, and wipe your heads, and wash your feet up to the ankles."

Imam Bukhari (may Allah have mercy on him) says that the Prophet Muhammad (peace be upon him) said that in ablution (wudu), washing each limb once is obligatory, and he (peace be upon him) also performed ablution by washing (the limbs) twice and also three times. However, he did not wash more than three times. And the scholars have considered it disliked (makruh) to be excessive in using water during ablution, lest people go beyond the action of the Messenger of Allah (peace be upon him).

Narrated Abu Huraira: Allah's Apostle said, "The prayer of a person who does Hadath (passes urine, stool or wind) is not accepted till he performs the ablution." A person from Hadaramout asked Abu Huraira, "What is 'Hadath'?" Abu Huraira replied, " 'Hadath' means the passing of wind."